There have been many static methods for dial indicator calibration using gage blocks, sine-bar and mechanical and/or optical mechanical displacement amplifying systems (see Patent Nr.24 26 156 West-Germany).
All of these calibration devices have a holder fixing the body of the dial indicator under calibration, the rod end of the dial indicator being held in contact with a linear displacement device. The operator reads the result of the measurement pointed by the dial indicator hand and compares it with the linear calibrated displacement of its rod imposed by the displacement device.
The difference between the two readings represents the error of the dial indicator for the corresponding calibration interval.
These methods have some drawbacks. They use a mechanical length standards, (like gage blocks, micrometric displacement, etc.), which is sensitive to temperature variation and aging, they are cumbersome and time consuming and the results are affected by operator errors in reading the dial indicator hand position corresponding to the rod displacement, and the calibration is performed over a small number of calibration intervals. The dial indicator rod is always in contact with the length standard during the entire calibration process, leading to deterioration of the latter.